Foamed inner tube

ABSTRACT

A ball inner tube used as a ball bladder or sold individually as a ball with better resilience, improved airtight performance and longer service is comprised of an inner tube designated material given the primary heating process, bound with a mixture of a foaming agent and the same material designated for the inner tube, and put under the secondary heating process at a temperature of 165° C. for the foaming agent to be integrated with the inner tube.

BACKGROUND OF THE INVENTION

(a) Technical Field of the Invention

The present invention is related to a foamed inner tube, and moreparticularly, to one used for balls that gives strong structure, longservice life and excellent resilience.

(b) Description of the Prior Art

The ball bladder is usually related to a direct type of an inner tube asillustrated in FIG. 1 of the accompanying drawings, an inner tube 1having its surface entwined with yarns 11 as illustrated in FIG. 2; ayarn 11 entwined inner tube 1 being further wrapped with an outer tube12 as illustrated in FIG. 3; or an inner tube 1 bound with fabrics 13 asillustrated in FIG. 4. However, these ball bladders are found with thefollowing flaws:

-   1. As the direct type of inner tube is molded and admixed with    sulfur, it tends to continuously expand along with the addition of    air.-   2. The inner tube entwined with yarns involves more complicated    manufacturing process.-   3. The sandwich type inner tube also involves complicated    manufacturing process and higher production cost.-   4. The fabric bound inner tube also involves comparatively higher    production cost.

Even though the yam entwined inner tube, the sandwich type inner tube orthe fabric bound inner tube is free of the problem of continuousexpansion when inflated, its impact force and resilience are stilllimited and fails to provide longer service life.

SUMMARY OF THE INVENTION

The primary purpose of the present invention is to provide a ball innertube that allows easier process and longer service life. To achieve thepurpose, the material for the ball inner tube is first given a primaryheating process and bound with a material blended with the same materialused for making the inner tube and an additive of foaming agent beforegoing through a secondary heating process for the foaming agent to beintegrated with the inner tube to become the final product of a foamedinner tube as a ball bladder.

The amount of the foaming agent to be added is adjustable depending onthe thickness and resilience as required for the particular ball innertube; and the foaming agent can be prepared in any color for thefinished product of the ball.

Other than rubber, TPU, PVC and other material identical with that usedfor the inner tube may be blended with the foaming agent for themanufacturing of the foamed inner tube.

The foregoing object and summary provide only a brief introduction tothe present invention. To fully appreciate these and other objects ofthe present invention as well as the invention itself, all of which willbecome apparent to those skilled in the art, the following detaileddescription of the invention and the claims should be read inconjunction with the accompanying drawings. Throughout the specificationand drawings identical reference numerals refer to identical or similarparts.

Many other advantages and features of the present invention will becomemanifest to those versed in the art upon making reference to thedetailed description and the accompanying sheets of drawings in which apreferred structural embodiment incorporating the principles of thepresent invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a construction of a direct type ofinner tube.

FIG. 2 is a schematic view showing a construction of a yarn-entwinedtype of inner tube.

FIG. 3 is a schematic view showing a construction of a sandwich type ofinner tube.

FIG. 4 is a schematic view showing a construction of a fabric bound typeof inner tube.

FIG. 5 is a process flow chart of the present invention.

FIG. 6 is a schematic view showing a construction of the presentinvention.

FIG. 7 is a table showing results of impact test conducted on thepresent invention and the prior art.

FIG. 8 is a table showing impact test data conducted on the presentinvention and the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following descriptions are of exemplary embodiments only, and arenot intended to limit the scope, applicability or configuration of theinvention in any way. Rather, the following description provides aconvenient illustration for implementing exemplary embodiments of theinvention. Various changes to the described embodiments may be made inthe function and arrangement of the elements described without departingfrom the scope of the invention as set forth in the appended claims.

Referring to FIGS. 5 and 6, an inner tube of the present invention ismade by first having a material designated for the inner tube to gothrough a primary heating process; and then the inner tube 1 is boundwith a mixture of a foaming agent and the same material designated forthe inner tube to be put through a secondary heating process at atemperature of 165° C. to become a formed inner tube serving as a ballbladder. Wherein, the inner tube 1 for being contained by the foamedlayer 2 is prevented from continuously expanding when inflated toachieve the same effects provided by the yarn entwined, fabric bound orsandwich type of the prior art while the foamed layer 2 allowsadjustment of its thickness and resilience depending on the requirementsof the particular ball to improve its hand-touch comfort and resilience.

The inner tube of the present invention also provides multiplefunctions. The foamed layer 2 can be made into any color as desired toforthwith become a finished product of a ball for direct sales.

Either in impact withstanding or in resilience, the inner tube of thepresent invention outperforms and inner tube of the prior art. As shownin FIG. 7, after the impact test of 5000 rounds, the present inventionmaintains its amount of deformation not greater than 3 mm in X, Y and Zaxes to ensure of its true circle. In 200 cm drop test, the presentinvention gives a bouncing height not less than 140 cm and the bouncingcould last 15˜20 rounds until it ends up in still.

As illustrated in FIG. 8 for further examination into the detailed dataavailed form the impact test based on X, Y and Z axes of a circle, after5000 rounds of impact, the variance of any of the prior art rangesbetween 4.0˜7.0 mm; and the present invention, 3.0 mm in thedistribution of 698 m, 697 mm, and 700 mm respectively for X, Y and Zaxes.

Advantages of the present invention include but not limit to thefollowings:

-   1. Resilience of the foamed layer gives hand-touch comfort and    protection;-   2. Reduced the inner pressure the outer layer of the ball as    confined by the foamed layer help ease off the pressure acting upon    the stitches made either by a sewing machine or by hand on the outer    layer for longer service life;-   3. Increased impact withstanding and resilience performance for the    ball, and the foaming multiplex can be adjusted for the resilience    of the ball depending on the appearance of the ball or customer's    needs; and-   4. Whereas the manufacturing process is similar to that for the    yarn-entwined type or fabric bound type, purchase of yarn-entwining    or fabric-binding machine is not required for cost saving.

Furthermore, the additional foamed layer of the present invention forthe ball bladder increases the airtight performance of the inner tube toreduce air leakage, natural deflation rate, and chances of being piercedthrough by sharp objects including rocks and nails.

It will be understood that each of the elements described above, or twoor more together may also find a useful application in other types ofmethods differing from the type described above.

While certain novel features of this invention have been shown anddescribed and are pointed out in the annexed claim, it is not intendedto be limited to the details above, since it will be understood thatvarious omissions, modifications, substitutions and changes in the formsand details of the device illustrated and in its operation can be madeby those skilled in the art without departing in any way from the spiritof the present invention.

1. A ball inner tube essentially comprised of an inner tube designatedmaterial given the primary heating process, bound with a mixture of afoaming agent and the same material designated for the inner tube, andput under the secondary heating process for the foaming agent to beintegrated with the inner tube.
 2. The ball inner tube of claim 1,wherein the designated material for the inner tube relates to rubber,TPU or PVC.
 3. The ball inner tube of claim 1, wherein the temperatureof the secondary heating process for binding the foaming agent the innertube is 165° C.
 4. The ball inner tube of claim 1, wherein the foamingagent is prepared in any color desired for the inner tube to be directlysold as a finished product of a ball.